One of the core beliefs of Judaism and Christianity is that God is omnipotent, able to do anything that is logically possible. But surprisingly, the Bible does not consistently support this idea. I’ve already written about the Tower of Babel, in which the Old Testament God appears to worry that humans will overmatch him if they complete the tower. And then, there’s the following little-known Bible verse:

“And the Lord was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron.”

—Judges 1:19

Although obscure among believers, this verse is famous among critics of scripture; it has even spawned a counter-apologetics wiki, fittingly titled Iron Chariots (and then there’s this amusing modern retelling).

Why God should have a problem overcoming iron chariots is not clear. In the context of the Bible it is utterly bizarre, almost as if it was inserted from a completely different religious tradition – it brings to mind the Celtic folklore about how cold iron was an effective repellent for faeries, ghosts, witches and other supernatural creatures.

On the other hand, it may just be that this verse was written when Yahweh was regarded as a local deity, supernaturally powerful but not invincible. In this respect, the biblical authors might have conceived of him as similar to the ancient Greek gods, who according to the Iliad could be wounded by humans. Iron chariots, in the world of the the Ancient Near East, were the most technologically advanced weapon of war in existence. They seem to have played a decisive role in conflicts like the Battle of Qarqar in 850 BCE, when an alliance of smaller kingdoms (including King Ahab of Israel, whom the Bible’s authors reviled) fended off an invasion by the regional superpower of Assyria.

It’s possible that the Bible’s original authors imagined God as not powerful enough to overcome this technology, and that the dogma of his total omnipotence was a later innovation. (By Judges chapter 4, God seems to have acquired the ability to defeat chariots.) If so, this verse might be a fossil of that earlier belief, preserved in the text like a prehistoric insect in amber. As a part of modern Judeo-Christian theology it’s like a puzzle piece that doesn’t fit, but if we take a more rational view of the Bible as a collection of human-written and human-compiled documents, verses like this may provide valuable clues about its origin and evolution.

Of course, the usual apologists have swooped in to try to explain away this verse within the framework of their own assumptions. The standard explanation for this verse is that the Israelites failed to drive out the Canaanites’ iron chariots because they were not obedient to God’s desires. However, the text itself does not support this guess: it mentions no such sin, and indeed, it says “the Lord was with Judah”, which one would not expect if Judah had been sinful or disobedient. Instead, it specifically identifies the presence of the iron chariots as the reason why the driving out of the Canaanites failed.